In a study published in the European Respiratory Journal 52 post mortem samples of lung donated for research were examined, in which dyes were used to carry out detailed analysis of 1,372 airways from the lung samples under microscope from 15 donations that has no reported asthma, 21 that had asthma but died from other causes, and 16 that died of the condition.
Analysis found fatty adipose tissue in the walls of the airways, even more was present in those with a higher BMI, and the increase in fat appears to have altered the normal structure of the airways and caused inflammation in the lungs. These findings may help to explain the increased risk of asthma among those who are overweight or obese. It was noted that more research is needed to find out if the buildup of fatty tissue can be reversed with exercise, in the meantime asthma patients should be encouraged to achieve a healthy weight.
“Being overweight or obese has already been linked to having asthma or having worse asthma symptoms. Researchers have suggested that the link might be explained by the direct pressure of excess weight on the lungs or by a general increase in inflammation created by excess weight,” says Dr Peter Noble, an associate professor at the University of Western Australia, in Perth who worked on the study.
According to Dr. Noble, “We’ve found that excess fat accumulates in the airway walls, where it takes up space and seems to increase inflammation within the lungs. “We think this is causing a thickening of the airways that limits the flow of air in and out of the lungs and that could at least partly explain an increase in asthma symptoms.”
“This is an important finding on the relationship between body weight and respiratory disease because it shows how being overweight or obese might be making symptoms worse for people with asthma. This goes beyond the simple observation that patients with obesity need to breathe more with activity and exercise.The observation points at true airway changes that are associated with obesity,” said Prof Thierry Troosters, president of the European Respiratory Society.
“This study adds to growing evidence that if you are overweight, it can make your asthma symptoms worse. If you struggle with your weight and have asthma, exercise is a great way to help manage your weight and can improve asthma symptoms such as coughing, wheezing and gasping for breath, which can lead to life-threatening asthma attacks. This is because getting active boosts your lung power and reduces breathlessness. You don’t need to run a marathon to be active with asthma, even doing gentle activity like gardening or going for a walk could improve your asthma symptoms,” said Emma Rubach, head of health advice at Asthma UK.
“Given the increasing incidence of obesity nationally and across the globe, the study could be of major importance in helping us understand why asthma remains a major health issue and identify new ways to improve asthma treatment. It is only a small study though, and we need to assess this in larger groups of patients and in other lung diseases,” said Dr Elizabeth Sapey, chair of the science committee at the British Thoracic Society, who went on to add that this is the first time body weight has been shown to impact the structure of the airways in the lungs.
